dogwoods burnt

I installed 6 cornus florida for an established client of mine. Nearly 2" caliber and transplanted 4 basically whips that she had. All the trees flourished for 5 months or so then started getting some mildew. Her arborist came and fertilized the large willow oaks above these dogwoods and sprayed for the mildew, but within 2 weeks or so all the dogwoods started to get crispy. Now all 10 dogwoods have every leaf brown and dead, but 2 have new shoots just today. Have you ever heard of this? Am I responsible for these? The arborist said only leaves with mildew would fall off, but now 99.9% of all leaves on all trees are dead. What do you recommend? ThanksPosted via Mobile Device

I have seen excessive powder mildew defoliage Dogwoods along with anthracnose. I have had problems with Lilac, and Gardenia's. Are these Dogwoods in an area with little or no airflow and too much moisture????? Poor air ciculation is the cause of my problems with mildew and mold. I treat all my problems with Propiconazole or Chlorthalonil. This stuff isn't as harsh to the plants as the more stringent commercial fungicides are. I don't want to cause leaf toxicity in our heat and humidity.
P.M. me for some more details on your trees..

There may be more at hand than just mildew..!!! What about samples taken to a fascility??